Catalytic asymmetric synthesis is known useful as a process of producing optically-active compounds including agricultural chemicals and pharmaceuticals. A catalytic asymmetric synthesis reaction using an optically-active catalyst (hereinafter referred to as “asymmetric catalyst”) has a great deal of potential in industry because it enables synthesis of large quantities of an optically-active compound using a very small amount of the asymmetric catalyst. Known useful asymmetric catalysts and asymmetric ligands constituting the catalysts are exemplified by an optically-active bisphosphinomethane represented by formula (5) below and a rhodium complex having this (see EP0997470A1).

Also known are a compound represented by formula (6) below, which is different in part from but structurally similar to the compound of EP0997470A1, and a compound obtained therefrom by deboranation (see JP 11-80179A and J.
Am. Chem. Soc., vol. 128, No. 29, pp 9336-9337).
For the purpose of developing asymmetric catalysts with improved performance, a vast number of optically-active diphosphine ligands have been proposed, including the above-described compounds. However, there still remains room for improvements on selectivity, catalytic activity, and the like in applications to some kinds of substrates.